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Uhe 36ome 
Optical Snstructor. 



• ♦ • 



Mow to Siecome an Sxpert 
in Sitting Slasses. 





»»»&»»»»»»»»»»»»»»»»»»» 



J 



Uhe 3tome 
Optical instructor. 

Owing to the Laws recently passed in various 
States, which prevent an impractical spec- 
tacle vender from selling spectacles with- 
out the knowledge of Optical Science, 
and to enable them to practice at 
home, I have compiled this Book of 
Instructions in a short system for 
the good of mankind, for ladies 
and gentlemen, young and 
middle aged people, to 
study Optometin^ at 
home in their 
leisure time 
and to en- 
able them 
to - 



- 






. 



Practice it in all the States of the Union. 



PUBLISHED BY 

PROFESSOR LOUIS CONIGISKY, D. O., 

Author and Proprietor, 
DUBUQUE, IOWA. 



1903 



Copyrighted and Entered according: to Act of Congress, June 1, 1903, 
in the office of the Librarian of Congress at Washington.] 

FIRST EDITION 



THE LIBRARY OF 
CONGRESS, 

Two Copies Received 

AUG 10 1903 

\\ Copyright Entry 
CUSS 0u XXcNo. 

y o 7 °\ is 

COPY B. 






F 



PREFACE 



In my experience with watchmakers and jewelers during" 
the past 26 years probably a thousand have expressed to me a 
desire and need for such a course of study. For these rea- 
sons I believe that a thorough course in this branch of sci- 
ence will meet with a hearty reception from the entire trade. 
This is an Independent Course. It is not necessary that you 
be a graduate in Optics in order to take this course. It is 
intended for the watchmaker and jeweler in his daily handling 
of spectacles as well as for the optician or oculist. It is as 
good for the student as for the advanced optician. 

The jeweler and watchmaker who has no intention of 
taking a regular optical course will find the practical work 
covered in this Instructor. It is worth a great many times 
the cost in actual dollars and cents. Under the subject of 
this book I teach the student to test and neutralize simple 
and compound lenses ; to know a first quality lense from a 
second or third quality; to locate quickly the axis of a cylin- 
der ; to find the center of a lense ; to- neutralize decentered 
lenses and prisms, and a valuable lecture on the accommo- 
dation and anatomy of the Human Eye, and this course con- 
sists of ninety-five questions and answers. Each lesson in- 
cludes a lecture and quite a series of practical questions on 
the subjects covered in the lecture. With each lecture is a 
review and explanation and re-explaining the questions of the 
previous lesson and setting the student right upon such 
points as he does not fully understand. In that way every 
subject is covered twice and the student is not permitted to 
form wrong impressions. Each individual receives a per- 
sonal instruction the same as if he were the only member of 
a class. 



INSTRUCTOR. 



This Instructor is for practicing to become a practical 
optician and refractionist. The student will be entitled to a 
diploma in any college if he thoroughly masters all the valu- 
able questions and answers. 

Composed by Prof. Louis Conigisky, the eminent 
Prussian Optician and Scientist who graduated from Prussia 
and also holds Diplomas of Honor of the most eminent Op- 
thalmic Colleges of this country. 



CONTENTS 



INSTRUCTION . PAGE . 

1. — To Study the Power of Lenses 8 

2. — To Neutralize Lenses and to find Convex or Concave Lenses. ... 9 

3.— From what the Eye is Composed 11 

4. — The Muscles of the Eye and Astigmatism, and to Examine 

the Eyes 13 

5. — The Clock Dial in Detecting Astigmatism 15 

6. — To Test the Eye by Fogging, and Crosseyes 18 

7. — After Fogging if you find that the Lines from 6 to 12 on the 

Clock Dial, etc 20 

8. — The Stenopaic Disc to find the good Meridian in Astigmatism. .22 

9. — Cataract Operation and Granulated Lids 24 

10.— With the Opthalmoscope we Look Into the Eye 24 

11.— Accommodation and Anatomy 25 

12— A Lecture on the Anatomy of the Human Eye ...27 

13. — A Lecture on Physiologie 32 




/'Persons having normal vision will be able to read thla 
print at e, distance of 14 inches from the eyes with ease and 
comfort ; also will be able to read it with each eye separately. 
Ifunabletodo so yonr eyes are defective and snould have 
immediate attention. When the eves become tired from read- 
ing or sewing, or if the letters look" blurred and run together, 
it is a sure indication that glasses are needed The lenses 
?old in the cheap goods are of unequal density and have 
imperfectly formed surfaces. Continued use of these poorer 
lens-23 will result in positive injury from the constant strain 
upon the mu^les of accommodation to supply the defects in 
fee >i • ass.'' 



INTRODUCTION 



To the Students : 

You will find that this course of instruction is a short, 
concise statement of the principles which underlie and com- 
pose the science of optics. There are several methods of 
testing eyes. I have adopted for this course the one which 
has proven the most accurate and altogether the most satis- 
factory to both the patient and the operator. If you will 
master this instruction and practice step by step you will be- 
come an expert optician. It will require study and practice. 
I have not used ten words to express a thought which could 
have as well been framed in two. I have stripped the subject 
of all superfluities and have devoted no space in proving 
my assertion concerning refraction. Special attention has 
been given to the measurement of the eyeball curvature of 
the cornea and length and strength of the ocular muscles. 
Considerable space has been given to the disease of the eye 
and to the nervous disturbance of the whole system due to 
the eye strain. 

The way to success is clearly pointed out. You relieve 
your fellow man by means of properly fitted glasses. Study 
each lecture carefully and answer the questions in writing be- 
fore taking up the succeeding study. Review each day all 
that you have studied the day before. Make every thought 
in these pages your own practice, each test as you proceed, 
and you may be assured that you will become a benefactor 
of mankind. 



INSTRUCTION-1 



Fig. 2 




It is first necessary to study the kinds and power of lenses. 
There are only five so it will be easy to remember them. 
We will start with the simplest form of lens which is called 
a prism. A prism is a wedge of glass. (See figure 1.) The 
thin edge is called the apex and the thick edge the base. 
Rays of light passing through the prism are bent towards 
the base. (See figure 2.) This displaces the object to an 
eye back of the prism. Thus a person would see the object 
much higher with one eye if a prism of 8 degrees was placed 
base down in front of the eye producing double vision. We 
will next consider the convex spherical lense. This lense is 
a combination of prisms with base in center. (See figure 3.) 
Rays of light striking the surface of this lense are brought 
to a focus or point back of the lense, the covexity of the 
lense determining the length of the focus. The thicker it is 



— 9— 

in the center the quicker the lines are brought to a focus. 
A concave spherical lense is a combination of prisms with 
the basis out and apex or thin part in the center. (See fig- 
ure 4.) The lines of light passing through these lenses 
are bent towards the base, and consequently diverge and do 
not come to a focus. A cylinder concave lense is the same 
thickness on the axis of the glass. It bends the rays of light 
one way. (See figure 5.) The dotted lines show the axis 
of the cylinder. Light passing through the cylindrical lense 
is focused to or diverged from a line ; in the spherical it is 
focused to a pin-head point, in the cylindrical convex the 
thick part is the axis. (See figure 6.) 

These are the five lenses used in correcting all errors of 
refraction and muscular insufficiencies. Learn these thor- 
oughly and you will understand what lense to prescribe for 
each defect. To illustrate : Suppose an eyeball is too short, 
you use a spherical convex lens to get a shorter focus. If 
the eye is too long you would use a spherical concave lens 
to diverge the lines of light. If only one meridian of the 
eye is at fault you use the cylindrical lense to bring forward 
or throw back the focus in that one meridian. The optical 
center of a lens is called the cone. (See figure 11.) To find 
the cone hold the lens about 6 inches from a straight edge 
card and move the lens until the edge of the card is continu- 
ous from top to bottom, (See figure 7 and 8.) Mark the 
the lens with ink over the line, then turn the lens half around 
and mark the line again. Where the line crosses is the cone 
or center. 

INSTRUCTION-2. 



Before studying this instruction answer questions num- 
bered. This will form a part of your final examination. 

1. What is the simplest form of a lens ? 

2. What is the thin edge of a lens called ? 

3. What is the thick part called ? 

4. Rays of light passing through a prism are bent in 
what direction ? 

5. What is a spherical convex lens ? 

6. How are rays of light bent in passing through this 
lens ? 

7. What is a spherical concave lens ? 



—10— 




8. How are rays of light bent in passing through this 
lens ? 

9. What is a cylindrical concave lens ? 

10. How does it bend the rays of light ? 

The lens shown in cut 
A. A. is out of center. To neu- 
tralize a lens use a concave lens 
to neutralize a convex lens and 
vice versa. 

A convex lens, if moved be- 
fore the eye will cause objects 
to move in the oppsite direction' 
The rapidity of the motion will A. A. 

depend on the strength of the glass. 

A concave lens will cause objects to move in the same 
direction as the hand moves. If you place a convex lens 
over a concave lens of the same strength there will be no 
motion and it is neutralized. In a cylindrical lense there is 
no motion of the axis, and to neutralize the lens the axis of 
both lenses must be parallel. When motion ceases the lens 
is neutralized. A prism is neutralized by placing another 
prism with base over the apex. When a card will show a 
continuous line the prism is neutralized. (Figs. 9 and 10, in- 
struction No. 1.) 

The spherical convex lens, also called a plus lens, cor- 
rects Hypermetropia and Presbyopia. It adds to-hplus sign. 
The spherical concave lens is also called — lens and corrects 
Myopia. It reduces in size ( — ) minus sign. 

Cylindrical lenses correct Astigmatism. 

Prisms correct muscular irregularities, often called 
"cross-eyes" or "squint-eyes." The proper name is Stra- 
bismus. 

These are the lenses and defects of eyesight with which 
we have to deal. Some eyes have but one defect, while 
others have two or even more* Compounding lenses so as 
to correct all the defects is the work that pays, both in cash 
or favor, with the people. It is simple after you master the 
use of the lenses. We bend the rays of light so they will 
focus upon the retina of the eye naturally. Refraction means 
to bend or break the rays of light. You should have a sam- 
ple of the five lenses to examine and experiment with. We 
will now pass on to the eye. 



—11— 



The eye is like a photographer's camera, 
picture upside down. We see with the brain. 




Fig. 4. 
Hypermetropia. 



wmu 



No. 7. 



It takes the 




Corrected. 



This eye is too short. The focus is made by the ciliary 
muscle which thickens the lens in the eye. 

Correct with spherical convex lenses. 




Myopia. 



Fig. 5. No. 5. 

Corrected. 



This eye is too long. The focus is made in front of the 
retina. The lines then cross and the picture is blurred. 
Throw the focus back with a spherical concave lens. This 
trouble makes a person near-sighted. 

Astigmatism is caused by an irregular cornea the clear 
part of the front of the eye. If the cornea is more convex 
one way than the other the lines are bent quicker at the con- 
vexity, and only one meridian can be focused properly. 



INSTRUCTION-3 



/ 
Before studying the instructions answer questions num 
bered. This will form a part of your final examination. 



12— 



11. What is the cone of a lens and how found? 

12. How do objects appear to move when viewed 
through a convex spherical lens which is in motion? 

13. How do they appear to move when using a concave 
spherical lens? 

14. How do you neutralize a lens? 

15. What is Hypermetropia? 

16. What lens corrects it, and why? 

17. What is Myopia? 

18. What lens corrects it, and why? 

19. What is Astigmatism? 

20. What lens corrects it, and why? 

21. When is a lens neutralized? 

The eye is composed 
of fluids and solids. Fluids 
are: The Aqueous Humor, 
the Crystalline Lens and 
the Vitreous Humor or jel- 
ly of the Eye. 

Solids are : The Scle- 
rotic, or white coat, and 
the cornea. The middle 
coat is the Choroid and Iris. 
The inner coat is the Reti- 
na, a layer of rods and 
cones which is spreading 
out of the optic nerve that 
connects the brain. 




Fig. 6. 
The Internal Arrangement of the Eye. 



The Crystalline Lens is back of the Iris and is sur- 
rounded by a muscl ecalled the Ciliary muscle. The 
lens hardens with age and the muscle is over taxed at 
the age of 40 years, so one needs plus glasses for reading. 
This change is called the Presbyopic change. Sometimes 
the lens hardens and turns white. This is called Cataract. 
Usually it can be absorbed, but sometimes it has to be re- 
moved.. It is ripe when the person cannot count figures at 
three feet. At the commencement of cataract the lens often 
swells and produces "second sight." The person can read 
without glasses because of the thickening of the lens in the 
eye. 




Figure 7. THE MUSCLES OF THE EYE. 

The eye is held in position and moved by six muscles 
called the Recti Muscles. If one muscle is short and the eye is 
turned in the case is one of manifest Convergent Strabismus. 
Persons may have a good deal of muscle- trouble and yet 
conceal it to the casual observer but a skillful optician readi- 
ly discovers the error. The names of the seven muscles of 
the eye and their functions are as follows : 

Superior Recti turn the eyes up. 

Inferior Recti turn the eyes down. 

Internal Recti turn the eyes in. 

External Recti turn the eyes out. 

The Superior Oblique is attached to the top of the eye- 
ball. It is called the "pulley muscle," as it runs through a 
pulley then back of the equator of the eye. 

These muscles are all attached at the apex of the orbit. 
The Inferior oblique is fastened to the under part of the eye- 
ball and back of the equator and to the bottom of the orbit 
in front of the equator of the eye-ball. The oblique muscles 
rotate the eye-ball when the head is moved from shoulder to 
shoulder in order that the picture may fall in all respects on 
the same part of the retina of each eye. The ciliary muscle 
surrounds the lens and regulates the focus. The Iris is the 
curtain of the eye and regulates the quantity of light admit- 
ted. The Macula is the sensitive part of the retina, the point 
of acute vision being straight back of the pupil. The mu- 
cous membrane covering the eye-ball is called the Conjunc- 
tiva and is continuous with that of the lids. 



— 14— 

INSTRUCTlON-4, 



Before studying this instruction answer questions num- 
bered. This will form a part of your final examination: 

-"' 22. Of what is the eye composed ? 

23. Name the fluids ? 

24. Name the solids ? 

25. Name the muscles of the eye and their functions ? 

26. What is the cause of Presbyopia? 

27. What lens corrects Presbyopia? 

28. What is Strabismus ? 

29. What lens corrects Strabismus ? 

30. What is Conjunctiva ? 

31. What is the Macula and where situated ? 

We will now pass on to a few of the terms used in the 
optical business, which the student will be expected to com- 
mit to memory. People like to hear you talk about Hyper- 
metropia, Strabismus and Astigmatism. They would much 
rather have you say their trouble is Convergent Strabismus 
than to say they are cross-eyed. 

Hypemetropia, Short eye-ball. 

Myopia, Long eye-ball. 

Presbyopia, Old age sight. 

Astigmatism, Irregular curvature of cornea or lens. 

Corneal Astigmatism, Irregular Cornea. 

Lenticular Astigmatism, Irregular Lens. 

Hyperopic Astigmatism, where the eye is short in one 
meridian and normal in the other. 

Myopic .Astigmatism, where the eye is long in one meri- 
dian and normal in the other. 

Mixed Astigmatism, The eye is long in one meridian 
and short in the other. 

Emmetropia, Eye in perfect focus. 
Strabismus, Cross eyes. 
Esophoria, Eye turns in. 
Exophoria, Eye turns out. 
Hyporphoria, Eye turns up. 
Cataphoria, Eye turns down. 
Hyperexophoria, Up and out. 
Hyperesophoria, Up and in. 



— 15— 

There are many other terms that one can learn. These 
cover all the optician needs, and to make this course as easy 
as possible and to save confusion to the beginner, we will not 
introduce anything- that is not absolutely necessary. This 
course will fit you to do 95 per cent of the work you need 
and it will not pay you to handle the other 5 per cent, as the 
conditions are diseases of the eye. 

We are now ready to begin the examination of the eyes. 
We need two cards. One has nine rows of letters of dif- 
ferent sizes and marked from the top down as follows: 



First line distance 120 feet. That is d— 120. 

a person with normal vision should see 
the line at 120 feet. Suppose your pa- 
tient is 20 feet from the card and can on- 
ly read that line. You will find his vis- 
ion 20-120 or one sixth normal. 



BF 



Second line distance 80 feet. If at 
20 feet he can only read the two top lines 
you will find the vision 20-80 or one 
fourth normal. 



LCP 



If he reads the third line 20-60 or d— 60. 

one third or so on. 



EDBT 



The lines run down to ten feet, so 
one can test in a ten-foot room if neces- 
sary, but it is better to have the card 20 d— 50 
feet away if possible. At 20 feet the eye 
is at rest. As an object comes nearer we 
begin to use our accommodation. 



PNOD 

D— 40. 

LTCPE 



INSTRUCTION-5 



D— 30. 



B LT EN 

Before studying this lecture use the d— 20. 

questions numbered. This will from a FRPOCLTIN 
part of your final examination. 



32. At what distance from the card 
should you have a patient sit, and why? 



D— 15. 

NOCTEPDLBF 



33. What kind of card should you D 1() - 

llse ? CPOELFBINTD 



—16— 

34. If the patient reads the 20 foot line sitting at 20 
feet what record do you make? 

35. What is Emmetropia? 

36. What is Esophoria? 

37. What is Exophoria? 

38. What is Hyperphoria? 

39. What is Cataphoria? 

40. What is Hyperexophoria? 

41. What is Hyperesophoria? 

The other card resembles a clock dial, with heavy black 
lines running from each hour mark to near the center. 

The lines, three in each group, should all look alike. 

You need a complete trial case of lenses and tests, in 
order to fit a patient with glasses. 

Test each eye separately when the patient looks at the 
card. This can be done by placing a card in front of first 
one eye and then the other. Never let the patient close his 
eyes or press it with his hands or it will blur the vision. 

Provide yourself with a pocket blank book and make a 
record as follows; Vision, right eye, 20-120 (or whatever 
your test may show;) left eye, 20-60. Pin-hole right eye, 
20-30, left eye, 20-20. 

The use of the Pin-Hole Test. If one-fourth or one-fifth 
vision is manifest use the pin-hole disc on one eye at a time, 
placing the solid disc before the other eye. This test is a 
black rubber disc with a pin hole in the center, which shuts 
off all but one ray of light which passes to the retina with 
out refraction. If this improves the vision there is an error 
of refraction and you can improve the sight. If this test 
does not help, the case is almost hopeless. 

After taking a record of each eye separately at 20 feet, 
place a plus 2.50 D. lens in each side of the trial frames, 
which you will have carefully centered before each eye. 
This will fog an emmetropic eye so much that your patient 
cannot read 20-120. If he reads 20-20 without glasses he 
has no Myopia or Astigmatism. If plus 2.50 fogs him com- 
pletely he has no manifest Hypermetropia. If he is under 
40 years of age he has no Presbyopia. 



17— 



The clock dial is used 
in detecting Astigmatism. 
If the lines from XII to VI 
are clear, as a rule he needs 
a minus cylindrical lens, 
with axis at right angles or 
at 180 degrees. If the clear 
lines are from (III) to IX 
he needs a plus cylindrical 
len, axis at right angles 90 
degrees. Do not over cor- 
rect. Stop a little short of 
full corrections in high de- 
grees. First correct any 
Myopia or Hypermetropia 
and then correct Astigma- Fl §- 8 

tism. Always try plus lenses first, then minus. 




If the eyes are not alike in focus, or if the patient can 
not see the card at 20 feet with one eye cover the good eye 
with the solid disc and bring the test card closer until the top 
line can be seen. Use the pin-hole test. If this improves 
the sight an error of refraction is indicated. Work out the 
case by fogging. Put on a plus lens strong enough to blur 
the top line. Place lens in the back cell of trial frame and 
neutralize the plus with minus lenses, commencing with 
minus 50 — 75 — 100 and so on until you get the best vision. 
The difference between minus and plus indicates the amount 
of Hypermetropia. Example: If it takes plus 5. 00D. to fog 
the top line and you have on minus 3.00D. to give the best 
distant vision subtract 3. 00D. from 5. 00D, and you have 
plus 2, 00D. remaining. If the lines on the clock dial are 
uniform in color and size this is the correction. 



Myopia, Astigmatism and Hypermetropia can all be- 
worked out under this system of fogging. Suppose you 
have a patient who reads 20-20 without glasses, you place in 
the cell plus 2.50D. both eyes, and they still read 20-20, you 
know the patient has at least 2.50D. of Hypermetropia. 
Put plus 5.00 in the frames and if some of the cards can be 
still read you have more than 2.50D. Reduce with minus 
lenses until your patient can read 20-20. The difference be- 
tween the minus and plus gives the exact amout of Hyper- 
metropia, 



—18— 

INSTRUCTION 



Before studying this instruction answer questions num- 
bered. This will form a part of your final examination. 

42. What is the object of fogging with strong plus 
lenses? 

43. Why will a plus 2.50D. spherical lens fog one per- 
son and not another? 

44. Of what use is the pin-hole test? 
45.- How can }^ou detect Astigmatism? 

46. When the III to IX is clearest, what lens is indica- 
ted as a rule? 

47. W T hen the XII to VI is clearest, what lens is indi- 
cated, as a rule? 

Suppose you have a patient who reads 20"50 both eyes 
and it takes plus 1.50 to fog the top line, you are almost 
sure, provided the clock dial looks even, to have a case of 
Myopia. Reduce the fog and stop when the patient reads 
20-20, or when the next stronger lens fails to improve the 
sight. The difference between the plus and the minus lenses 
will measure the Myopia. 

Do not use over 1.50 or 2.00D. difference between the 
lenses in a pair of glasses. Fit the good eye and let the 
poor eye go uncorrected beyond 2.00D. Example: If it 
takes plus 1.00 on one eye and plus 4.00D on the other eye 
to get the same vision give only plus 3.00D. on the poor eye. 
Give the weakest minus lens that will make him see the 20 
foot line at 20 feet. Some eyes can not be brought up to 
perfect conditions. 

After the age of 40 the Presbyopic change commences 
and progresses to 65 or 70. This is caused by the harden- 
ing of the Crystalline lens and shrinking of the eye-ball. It 
will usually take plus 1.00D. lenses for reading at 45 years; 
plus 2. 00D. at 55 and plus 3. 00D. at 65. 

Always test for distant vision first, then test at 14 inches. 
On the reading test card are letters ranging from the finest 
to large size, after correcting the distant vision show the 
reading card to the patient, and if he can only read to 20 it 
indicates that a 20 inch lens or plus 2.00D. len will give him 
perfect vision. After correcting any errors of refraction 
hold 8 degrees of prism in front of one eye, base down and 
have the patient look at a door knob or candle. 



-19— 

This lens produces double vision. If one is seen direct- 
ly over the other it shows the external and internal muscles 
are properly balanced. Turn the base of the prism in and 
he will see two candles horizontally. If one is not higher 
the other the superior and inferior recti muscles balance. 

A person should be able to overcome 5 or 6 degrees of 
prism base in and 15 degrees base out. Xo test of the eye 
is complete unless the strength of the muscles is ascertained. 
When you place the base of the prism in your test the 
strength of the external muscles; base out the internal. 

To exercise the muscle, place the apex of the prism over 

it. To rest the muscle place the base of the prism over it. 

Suppose you have a patient who can overcome on a 20 
foot test 20 degrees of prism, base in, and only 5 degrees, 
base out. You know at once that the externals are to strong 
for the internals in close work. Prisms are indicated base 
in. A person should overcome from 1% to 3 degrees, base 
up or down, as the superior and inferior recti muscles should 
be of equal strength. 

If one eye turns in set the base of the prism out. If the 
eye turns out, set the base of the prism in. A prism which 
brings the objects together measures the defect. The cor- 
rection may be divided and half placed on each eye. In Hy- 
permetropia the eye often turns in, there being a associated 
movements between accommodation and convergence. 

Accommodation is the act of thickening the lens of the 
eye for close work. If the eye ball is short, the accommoda- 
tion has to be used for distance. When the eye is normal, 
the accommodation is used when the object looked at comes 
within 20 feet, and at the same time the eyes converge, or 
come together. If you look at the end of your nose you 
have the appearance of being cross-eyed. 

Many cases of cross-eyes in children may be cured with 
strong plus lenses. Let the lens fog the 20 foot line if the. 
patient will wear it. 

Care should be taken in prescribing prisms. Some 
writers claim the use of prisms criminal, but we have had 
some excellent results where others, who were afraid, 
failed. Use care and judgment. 



—20— 

INSTRUCTION 7. 



Before studying this instruction use the questions num- 
bered. This will form part of your final examination. 

48. After fogging the vision with plus lenses, how do 
you proceed, and when should you stop? 

4 ( ). How much difference can be made in glasses 
where the eyes are not alike in focus? 

50. Do you prescribe the weakest or strongest lens 
with which a patient can see 20-20 in Hypermetropia? 

51. In Myopia? 

52. What is Presbyopia, and how corrected ? 

53. How can you prove that the external and inter- 
nal muscles balance ? 

54. How much stronger should the internal muscles 
be than the external ? 

55. How many degrees of prism, base in, should a 
person overcome? 

56. How many degrees of prism base out, should a 
person overcome? 

57. Base up or down, how many degrees prism should 
a person overcome? 

58. If the eye turns in, how do you place the base of 
the prism ? 

59. If the eye turn out, how do you place the base of 
the prism ? 

In Strabismus, if the eye turns out, give full correction; 
if it turns in, half correction. 

In fitting frames care should be taken to see that the 
nose piece is not too high or too low, too wide or too nar- 
row. The patient must look through the center of the lens. 
To measure the pupilliary distance, hold a rule with the 
end in front of the center of the pupil of one eye. Where 
the center of the other pupil comes on the rule is the measure. 
It will run from 2 inches in children to 2 and eight-six- 
teenths in adults, the average being 2 and six-sixteenths. 
Occasionally we have one 2 and three quarter inches. 
Nose glasses are not as satisfactory as spectacles. Rimless 



—21 — 

spectacles are easily broken, and people should be warned 
about them. A few hours practice on yourself or friends, 
with the trial case, will fit you for active work. Place a 
plus 3. D. in frame and your eye is made Myopic. Correct 
this with minus sphere of same number. Place a minus 
2. D. in frame and this makes the case Hypermetropic, and 
that is corrected with the plus lens. It is the same with 
the cylindrical lenses and prisms. If you will practice on 
yourself you will understand better the cases you meet. 

When the patient tells you how the chart appears you 
will recognize the case as the same you produced in your 
eyes with a certain lens and you will know immediately 
what corrects that trouble. 

The lenses are numbered by the Dioptric system, a me- 
ter (40 inches), being the unit of measure. A lens of 1.00 
D. strength focus at 40 inches or one meter. 200 D., being 
double the strength, focuses at half the distance or 20 
inches 0. 50 D. being half the strength focuses at 80 inches. 
Divide 40 by the Dioptric measure of the lens and you have 
the distance in inches at which the line focus. 4.00 D. 
equals 10 inches, 5.00 D. equals 8 inches. 

Care must be taken in writing a prescription. 

1st. Let your patient wear the correction as long as 
possible in your office to see if it is comfortable. 

2nd, Be sure to use the — |— or — sign before your 
sphere, or cylinder, and state whether prism are to be 
base in or out. 

3d. Exercise care in fitting frames to have them set as 
close to the eyes as possible without the lashes touching 
the glass. 

4th. See that the temples are long enough and wide 
enough to be eomfortable. 

Blanks are furnished by optical companies to be used 
in writing prescriptions. 

On the two cell trial frames the outer cell revolves. It 
is marked in degrees. If you use a plus 1.00 D. spherical 
lens combined with a plus 50. cylindrical lens, placing the 
axis perpendicular, you will find the pointer making 90 
degrees. In this case you would prescribe: Right eye, plus 



—22— 

1.00 D. spherical, combined with plus 50 D. cylindrical 
axis 90 degrees. Left eye — what your test indicates. 

After fogging with plus 2.50 spheres and gradually re- 
ducing the fog with minus spheres, if you find that the 
lines from VI to XII on the clock dial are very much clear- 
er than the others, place a minus .25 D. Cylinder with axis 
at 180. If this does not make all lines appear alike trv, 
successively — .38, — .50, — .62, etc., until all lines appear 
equally clear. 

INSTRUCTION 8. 



Before studying this instruction answer questions 
numbered. This will form a part of your final examination. 

60. Why should a person look through the center of 
their lenses ? 

61. At what distance should you test for muscle 
trouble ? 

62. How will you proceed to test eyes ? 

63. Explain the Dioptric system ? 

64. Name a few important points in fitting frames. 

You may have this correction in your trial frame: 
-|-plus 1.50 D. sph. 3 (combined with) — .62 cyl., axis 
180. Suppose this gives 20-20, or perfect vision. Before 
ordering the glasses you should transpose this into all plus 
and let the patient try them. This is to assure yourself 
that you have not made a mistake. To transpose a-!-, — 
into all -|-. 

Subtract the cylinder from the sphere. Bring down 
your cylinder, but change the sign and turn the axis 90 
degrees. 

Example: -|- 1.50 Sph. — .62 cvl. axis 180 equals -|- 
.88 Sph. -|- .62 Cyl. axis 90.° 

The records you should take in each case are: 
Distant vision (each eye). 
Fogging with -|- 2.50 (each eye). 
Astigmatic (each eye). 
Pinhole if necessary (each eye). 



—23— 

Abduction (base in) both eyes open. 

Adduction (base out) both eyes open. 

Sursumduction (base down or up) both eyes open. 

Presbyopia (each eye). 

Prescription needed. 

Frame measure. 

Kind wanted. 

Name — age — address. 

Symptoms described. 

Occupation . Price charged . 

Disease of eyes or lids. 

The stenopaic disc is a black rubber disc with a narrow 
opening across one way. 

This is very useful in locating the good meridian in 
cases of astigmatism and tells you the point to place the 
axis of cylinder used. Place it in revolving cell, having the 
other eye covered with solid disc. Move it slowly and 
stop when vision is best and the chart looks clear to your 
patient. Read your trial frame at the point of opening, 
and place the axis of your cylinder at this point. 

The Maddox muscle rod is an aid in locating muscle 
trouble. It is used with both eyes open looking at alight- 
ed candle. One eye sees the candle, the other a streak of 
light. If one is in front of the other, the muscles balance. 
If not, use a prism of eufficient strength to bring them 
in line. 

Spasm of ciliary muscle is caused from over-taxing the 
eyes. It can usually be cured with strong plus lenses. It 
is sometimes necessary to treat the eyes with antropine. 
This treatment paralyzes the ciliary muscles, and it grad- 
ually relaxes. It dilates the pupil of the eye. It takes sev- 
eral days for this to wear off. This trouble usually occurs 
in Hypemetropia. The ciliary muscle being forced to focus, 
the distant vision is never at rest. This over work causes 
the spasm. When testing the eyes always ask if they see 
floating spots. Also whether they see flashes of light. 
These arc often signs of disease of the retina. 



—24— 

All disease arises from impure blood or nerve exhaus- 
tion. It is useless to treat the symptoms. The true sci- 
ence of healing is to remove the cause. Natureisthe great 
healer. Color blindness is a congenital with about 4 per 
cent, of men and 1 per cent, of women. It is a lack of per- 
ception of the difference detween the seven primitive pris- 
matic colors, viz: red, orange, yellow, green, blue, indigo 
and violet. It is often acquired from tobacco habit or 
other poisoning. 

INSTRUCTION 9. 



Before studying this instruction answer questions 
numbered. This will form a part of your final examination. 

65. Transpose -|- 3.00 D. Sph. C — 1.25 CvL 
axis 180° 

66. Transpose — 2.75 D. Sph. C -|- 2.00 CyL 
90.° 

67. Transpose -|- .50 D. Sph. O — 50 D: CyL 
axis 180.° 

68. Why should you keep a complete record of every 
case? 

69. Why is it necessary to keep a record of each eve 
separately ? 

70. Give meaning of terms Abduction, Adduction and 
Surs-umduction. 

71. Is it important to test the muscles of the eye ? 

Iritis is another dangerous and painful disease. The 
pupil contracts, eyeball becomes highly inflamed, the iris 
has a muddy appearance. There is dread of light (photo- 
phobia). This disease should be treated ot once by a phy- 
sician as there is danger that the iris will become attached 
to the lens. 

INSTRUCTION 10. 



Before studying this instruction answer the questions 
numbered. This will form apart of your final exam ination. 

72. What is spasm of ciliary muscles ? 



—25— 

73. How is it cured ? 

74. Of what are floating spots the sign ? 

75. What is Pterygium ? 

76. Name the three stages of conjunctivitis ? 

77. What is color blindness ? 

78. Define Glaucoma ? 

79. Describe the symptoms of iritis. 

In Hypermetropia the Ciliary muscle is forced to over 
work. This causes dizziness, pain in the eyes, blurring of 
sight while reading, nervous dyspepsia, cross eyes, and is 
very common. 

In Myopia the patient squints, has headache and holds 
objects close to his eyes: 

In Astigmatism the strain produces headache and nerv- 
ous exhaustion. From correction people receive prompt 
relief after doctoring for years. 

I cure all these diseases by conserving the nerve forces. 
I remove the cause, eye strain nature comes to the rescue 
and a cure results. 

With the Opthalmoscope we look into the eye and ex- 
amine the retina. (See figure 4, Page 29). Each student 
will derive great benefit from the use of this instrument 
in examination, as many diseases may be detected by 
scrutinizing of the retina. 

INSTRUCTION 11, 



80. What is the cause of disease ? 

81 . How can it be cured ? 

82. Through what nerve do we get a reflex action ? 

83. What reflex is produced by strain of the ciliary 
muscles ? 

84. What are the nervous symptoms in Myopia ? 

85. What nervous troubles are caused by astig- 
matism ? 

86. State the difference between an error ofrefraction 
and an error of accommodation? 



—26— 

£7. What parts of the eye would be touched by a line 
passing through the optical center ? 

88. What regulates the amount of light which enters 
the eye ? 

89. Why is it often possible for a hypermetropic per- 
son to see perfectly at a distance ? 

90. Do you use the Opthalmoscope? 

91. Have you taken optical instructions before ? 

62. About how many hours have you studied on 
this course ? 

93. Have you a trial case, and have you used it as 
directed ? 

94. Have you been helped in any way by this course? 

95. Do you want to buy a trial case, or other optical 
instruments. 





8 



\T< Mirn 1 1 1 1 j 1 1 , 1 1 ij n 




Artificial Human Eyes* 

And Hoiv to Insert Them 



LECTURE ON THE ANATOMY OF THE HUMAN EYE. 

Our present exact knowledge of accommodation, sim- 
ple as it now seems to us, has only been arrived at after 
an immense amount of patience and laborious research, 
and within the last thirty years has finally received the 
character of an exact science. I must ask patience from 
some of the readers, as it is impossible to explain the mat- 
ter before us without stating some facts about anatomy 
of the eye, and therefore I ani compelled to make use of a 
few scientific phrases, but I hope this chapter will not be 
overlooked on that account, for it is the very one which 
conveys the information intended mainly to be given. 

The eye is a globular body composed of three envelop- 
ing coats holding in place the contained liquids or humors, 
which are of a more or less resisting consistency. The eye 
rests in a hollow bony socket, (see fig. 6, page 12) through 
whose walls pass the optic nerve, vessels, etc., serving to 
maintain in the normal functions of the eve. The socket is 
lined with soft tissue, forming a yielding surface within 
which the eye moves and which also mitigates the sever- 
ity ol blows upon the visual organs. 

The eye is moved by six muscles, (see fig. 7, page 13 \ 
originating at the baek of the socket and passing forward 
to their attachment upon the front of the globe, The mus- 
cles move the eye in all directions, and a contraction or a 
paralysis of any of them produce the deformity called 
"cross-eye" which may usually be relieved by a suitable 
operation upon the affected muscles. 

The outer coat of the eye is called the sclerotic, and is 
is hard, tough and unyielding, being really the skeleton of 
the eye, maintaining it's shape and holding the other por- 
tions in position. It is white and glistening in appearance 
and is indicated, when reference is made to the white of the 
eye. At the extreme front of the eye is seen a transparent 
bulging membrane, resembling the crystal of a watch, 
called the cornea. This is really a continuation of the scle- 
rotic, only it is transparent, while the sclerotic is opaque. 
It performs the same function to an eye that & window 
does to a room, viz: it enables light to pass to the interior 
and allows one to look out and observe what is going on. 
If a window to a room was frosted or walled up,itsinteri- 



—28— 

or would be dark arid one could not look out through it. 
So it is with the eye; the cornea is the window of the eye. 
If it becomes scarred or destroyed, light fails to pass inside 
and sight is destroyed. It will thus be seen how impor- 
tant it is to maintain the cornea in it's integrity, and to 
seek competent advice in case it is even slightly diseased, as 
a minute scar or opacity of its tissues especially if situated 
directly over the pupil, may practically destroy fine vision. 
The cornea is a continuation of the sclerotic of the outer 
membrane of the optic nerve, and the latter a continuation 
of the outer membrane of the brain; thus the eye is in re- 
ality a portion of the brain and should be regarded with 
the respect usually accorded to that important structure. 

Passing inward the next coat of the eye is a dark, 
bloody membrane called the choroid. It plays an impor- 
tant part in furnishing nourishment to the eye, and 
it passes forward to the interior portions of the eye and 
forms a muscle called the A f 

ciliary muscles or muscles 
of accommodation which 
envelopes the periphery, 
of the crystalline lens, 
(Fig. 3). As the choraid 
passes still further for- 

r . 1 FIG. 3. — (8howing the act of accom- 

Ward it merges mtO What modation. The left side is in a state ofrest; 

, i . the rijjht side is in the act of accommodation 

IS Known as tile lriS, as can be seen by the increased thickness or 

Which gives tO the peO- convexity of the lens.) 

pie's eyes their characteristics color of blue, brown, black, 
etc. The iris is a thin membrane or curtain situated just 
back of the cornea, with a hole punched in it's middle, 
called the pupil. 

In the iris are found two muscles, which contract and 
dilate the pupil in order to control the amount of light 
entering the eye; thus if the eye is exposed to a bright light 
the pupil contracts; if thelight isdimit dilates. Although 
the pupil is merely an opening, it nevertheless looks black 
because of the apparant lack of illumination, just as a door 
into a closed closet looks dark because the interior is not 
illuminated. If, however, daylight is allowed to pass 
through any portions of the closet wall, or if we stand up- 
on the threshold with a lighted lamp the black area of the 





—29- 

doorway is lost, and the contents of the closet are re- 
vealed. If light rayscan be thrown into the interior of the 
eye and if the head of the observer does not block the way 
to the transmission and reception of these rays the inside 
of the eye can be accurately observed. This is done with 
an instrument called the Opthalmoscope, which is practi- 
cally and simply aper- 
i orated mirror held in 
front of the observer's 
eje by which light is 
reflected into the ob- 
served eye and an im- 
pression of it's con- 
tents transmitted back 
through the perforated 
mirror to the eve of Fig 4. 

the the observer. (See Fig. 4) In this way both eyes 
are directly within the light rays, and no obstruction 
exists to interfere with their mutual interchange. By 
means of the Opthalmoscope the optic nerve, retina, cho- 
roid, etc., may be clearly seen, and the wonderful picture 
of life in veritable action accurately observed. 

As the optic nerve enters the eyeball at it's posterior 
extremity it expands into a thin membrane which lines the 
interior of the globe and forms the delicate perception tis- 
sue called the retina or third coat of the eye. It is a direct 
continuation of the optic nerve and brain and into it's 
sensitive substance are impressed the images of all we see, 
which are then transmitted via the optic nerve to the pos- 
terior portion of the brain, where they are interpreted at 
sight. The eye resembles a camera and like a camera, 
"takes pictures. " The sclerotic corresponds to the box of 
the camera, the choroid to its black interior for the absorp- 
tion of superfluous light, the retina to the receptive film, 
upon which the picture of an object is impressed, the pupil 
to the opening in front of the box, through which light 
passes, and the lens and humors to lenses and spaces inside 
the photographer's box. One point of difference however, 
is noticable, viz: the film of the camera can receive only 
one distinct impression, which it retains, but the film of 
the eye or the retina, can receive billions of impressions, 



—30— 

which appear and disappear with therapidity of thought, 
as the gaze is directed at changing and ever changing 
objects. 

As we have tw r o eyes, so we see two impressions of 
every object upon w r hich we gaze, but these two impres- 
sions are merged or focused together, so that we appar- 
ently see only one object, but by each eye looking at the 
object from a some-what different aspect, the impression 
obtained is much more general and comprehensive than if 
observed by only one eye. Sometimes the ocular muscles 
do not work harmoniously together in focusing the two 
eyes upon one object, under which circumstances the intui- 
tive muscular and nervous struggle for the proper adjust- 
ment often produces tired eyes and headache. Unless one 
eye gives up the struggle, and a "crossed eye" and some- 
times double vision results. 

There are three liquids of humors inside the eye — name- 
ly, the aqueous and vitreous humors and the crystalline 
lens in its capsule or envelopes. The Aqueous humor is sit- 
uated just back of the cornea. It is watery in consistency 
and is reproduced in a few hours after evacuation. The 
vitreous humor is situated in the back of the eye, is thicker 
in consistency and occupies about two-thirds of the ocular 
space and is not reproduced after evacuation. The crys- 
talline lens is swung between these two humors by a circu- 
lar ligament attached to the inside of the eye and sets just 
back of the pupil. It is harder than the other two humors 
and it is surrounded at its periphery, as has been said, by 
the ciliary muscle or the muscle of accommodation, as it is 
sometimes called. 

These muscle produces a perpetual variation in the con- 
vexity of the lens to correspond with the size or distance 
of an object. If a small or close object is gazed upon the 
muscles of accommodation causes the lens to become more 
convex and clear vision is obtained. If a larger or distinct 
object is to be seen, the lens becomes less convex and vision 
is again adjusted. These changes are constantly occuring 
and the activity of this little muscle can be imagined, and 
it will be readily understood that when inordinately used 
under improper circumstances, it becomes fatigued and 



—31 



characteristic eye and head pains result, which sometimes 
require rest, improved health or glasses to correct. 



The healthy lens are 
clear and transparent, but 
sometimes it becomes 
milky or white, and then 
the eye is said to have a 
cataract, which can for- 
tunately be cured by re- 
moving the opaque lens 
(fig. 5) and after replac- 
ing it by a strong convex 
glass lens in a spectacle 
frame, which acts as a 
substitute and re-establishes 




FIG. 5. — (Showing the operation for 
the removal of oataractous or opaque lens. 
The lids are held apart by an instrument. 



good 



vision. 



The eyelids are outwardly covered with skin, and in- 
wardly lined with a mucous membrane called the conjunc- 
tive, which becomes reflected into the eyeball over the white 
sclerotic as far as the corneal margin. It is thin and trans- 
parent and hardly visible in health, but when inflamed be- 
comes red and swollen and more or less obscures the under 
lying sclerotic. The conjunctive is the seat of a majority 
of eye diseases and shows it- 
self in the many varieties of 
"sore eyes" granulated lids, 
(fig. 6) etc. The body of the 
lid between the skin and con- 
junctive is composed princi- 
pally of muscles which move 
it and a little piece of tough 
tissues which holds it in 
shape. The lids are fringed 
with lashes, which serve to 
enchance the personal ap- 
pearance and to protect the 
eye from outside objects, 
such as sand, cinders, etc. 

FIG. 6. — (Showing the appearance 
of "granulated lids." The upper lid is 
turned over, showing under surface.) 




—32— 




meant 



Som times the lashes become distorted in their position 
producing a condition 
known as "wild hairs" 
(Fig. 7) causing a con- 
stant a painful scrap- 
ing on the sensitive cor- 
nea, which often causes 
blindness. It can usu- 
ally be cured by an op- 
eration. 



The tears are man- 
ufactured in a gland 
over the eye and pass 

Onto the ball. They by ; the condition called "wild hair 

are conducted towards the nose and pass into the little 
tear-ducts at the inside of the eye in the lids, whence they 
pass into the nose. (fig. 8) 
Sometimes the tear-ducts be- 
come more or less closed, 
producing what is known 
as " watery eyes" or con- 
stant presence of observable 
tears from their inabilitv to 
pass down through the pro- 
per channels. This condi- 
tion can usually be cured by 
an operation and treatment 
upon the tear-duct, which 
opens it up and maintains 
its draining qualities with 
out destroying its healthy 
physiological action 




FIG. 8. — (Showing the gland which 
makes the tears and apparatus which 
conveys it over the eye into the nose.) 



Lecture on Physiologic and Histologic 

There is a new question to consider, what has your 
sanity to do with your eyes ? or, to put it the other way, 
what have your eyes to do with your sanity ? The exter- 
nal impressions upon the brain of an individual who can- 
not see but a few inches from his nose, and in whose eyes 
the rays of light never focus correctly, must be very differ- 
ent from the impressions received by a normal eye, so differ- 



—33— 

ent as to be abnormal; and though the optician may, with 
glasses, correct to some extent the defect of the eves, he can 
never, by mechanical means, cure the physiologic and hist- 
ologic faults behind the eye, or restore to normal condition 
conceivable pathologic nerve paths, and nerve centers 
through which impression of the outer world must pass to 
the cerebrating centers of such a brain, much less is he cap- 
able of effacing from the brain the false impressions re- 
ceived before glasses were worn, or still imperfect and 
therein false and abnormal impression received since wear- 
ing them. 

An impression from without in transit would at first 
encounter the distorting influence of defective eye, then is 
twisted from the normal along presumably corresponding 
defective nerve and ganglionic paths, and lastly is received 
and metamorphosed by presumable corresponding brain 
cells. The reflex of such cerebration is an expression of an 
idea and the idea represents the man. 

Now you can no more get strictly correct ideas, nor- 
mal ideas from a congenitally defective head, thanyoucan 
get pure water from a sewer. 

Every person congenitally blind or partially blind i& 
mentally abnormal. This is a startling statement, as the 
orator of the old school would say, a statement to give us 
pause. 

Defective vision is consequently a direct cause of insan- 
ity; prevalence of eye defects is a matter of vital interest 
to all who have eyes, whether they see with them or not. 

A person's brain is his world, each one lives in his own 
world, and what that world is does not depend on the eye 
it depends on the brain. One sees with the brain, Thai a 
defect of the eye may disturb the brain and be a contribut- 
ing cause of insanity, is to a certain degree true, because 
insanity results from physical causes; any strain may tend 
to produce insanity — eye strain as well as any other. 

The question as to the relation existing between the 
eye strains and diseases of the brain cannot be answered 
without taking into consideration certain psychological 
tacts. The brain is simply a store-house or rather a stom- 
ach for the reception of all kinds of impressions, whether 

LcfC. 



from the eye or other special senses, and when they are re- 
ceived they are digested and stored away as a basis for 
thought. If any avenue be closed or in any way limited, 
unless it be sufficiently made up by other of the special 
senses; certainly a weakness or perversion of mental pow- 
er may result. 

However, to say that nearsightedness or other disease 
due to a lack of symetry of the eyeball is a proof of brain 
degeneration, or even is a contributing cause to insanity, 
further than the weakening or disuse of any other organ 
which disturbs the general health and nutrition and 
which depresses the general system is a cause, is not ac- 
cepted. 

We must remember certain fundamental facts of psyc- 
hology. We do not see with our eyes, or hear with our 
ears, or smell with our nose, though we do all these things 
through them. The eye is simply a mechanical instrument 
to the back of which a nerve is attached that conveys the 
rays of light to the brain, or rather so irritates the nerve 
as to produce a corresponding impression upon the brain. 
If this same impression could bemade without themedium 
of the eye, vision would result equally well. As a matter 
of fact, in certain pathological conditions of the brain, we 
do not have this phenomenon. Hallucinatians which are 
so frequent in the insane and w^hich are not uncommon in 
the sane are to be thus explained, in our dreams at night 
visions are frequent, and we do not see though darkly and 
often without vivid memory. 

The child who is born blind, and later, by a cataract 
operation with the aid of glasses is given normal vision, 
does not see as the educated eye sees. W r e see with our 
brain and must digest our impressions before we can judge 
as to what we do see. This is an education in itself and 
can only be acquired by practice. The distance between 
our twQ eyes is simply a base line, and by this we calcu- 
late objects. The person who has lost one eye, still has in 
one sense good vision, — in another not, as he is at fault in 
accurately calculating. He cannot pour his tea or hit the 
open mouth of his ink-well. 



—35- 

The child who cries for the noon probably thinks it no 
farther off than is the light of a candle. A person sudden- 
ly restored to sight is helpless until he learns to know and 
judge of what he does see. The man who loses his arm 
and complains that he can feel his hand and that his fin- 
gers ache actually does feel a pain, which by mental educa- 
tion he refers to his hand; yet it is but the irritated end of 
a nerve which once did supply the hand even amongst so- 
called normal individuals. Where all the special senses are 
perfect, yet there is a vast difference as to what one re- 
members. The artist will look at a face and at a tree or 
a landscape, go home, vividly recall it and be able to re- 
produce it. The effect produced by the Wagner operas on 
different individuals bears a direct relation to brain culti- 
vation and aptitude. The ears of listeners are probably 
normal, but what to one is divine harmony and pleasure 
unspeakable, is to another unmeaning jangle of inharmoni- 
ous sounds. 

It is thus seen that with perfect organs the under- 
standing or memory is everything, and for this reason the 
kingdom of each individual is his own brain and the limi- 
tation is only a brain limitation. Dr. F. W. Southard, 
who as a specialist in the diseases of the eye, enjoys a fame 
in the capitals of Europe as well as at home, regards the 
eye as of the higher importance in fixing and preserving 
mental balance. 

The defective eye regarded simply as an organ, will not 
cause insanity or brain disturbance. It's the strain on the 
brain brought about by the effort to overcome that defect 
that does the damage. The phisiological disturbance 
comes not from the image, but from strain. Such strain 
is in many cases the cause of chorea, and of a nervous con- 
dition that emulates epilepsy, and when it is very severe 
and long continued and other condition are favorable, it 
is possible for it to cause insanity. When the effort to see 
— to overcomeeye defects goes beyond the normal, it causes 
an excessive draft on the energy and drawing on the prin- 
cipal, as it were, which is likely to exhaust the capital fast- 
er than it can be supplied — bankruptcy break-down. 



—86— 

Tha importance of correcting errors of vision cannot 
be exaggerated. Through his eves the child gains his first 
ideas of the external world, through them, aided by touch 
and muscular sense, he learns the direction, size and dist- 
ance of objects in space. Very early in life his mind begins 
to take cognizance of visual impressions and upon his abil- 
ity to correctly interpret them may depend his whole fut- 
ure life, either for success or failure. If, through any de- 
fect in his eyes, false or distorted pictures of objects are 
formed upon the retina, then will his notions of external 
world be erroneous, his judgment unreliable and but little 
dependence can be placed upon its statements concerning 
events coming under his personal observation. There 
should be no cause of surprise if the child provided as he 
is with a most marvelous organization, made to collect, 
transmit, assort and store up in the cells of the brain the 
products of the visual impression for future reference 
should misinterpret their meaning, if the pictures of objects 
looked tipon the imperfect. That the mind maybe able to 
correct wrong visual impression it must posess a true 
standard: such cannot in the nature of things exist; it 
comes, and must always come, through experience. 

Before the fifth year a childs perceptive powers have 
begun to unfold. He is gradually learning the power of 
attention. Slowly and surely his mind is being filled with 
a desire to know, his former uncontrolled inquisitiveness 
is gradually giving place to acquisitivenes. He asks for 
the meaning of things. His mental horizon expands. He 
originates ideas, he is begining to think. 

During the period of receptivety the eyes should be 
capable of seeing the most accurately. At this period of 
life should there be errors of refraction they are most easily 
and satisfactorily corrected. 

The study of anatomy and physiology teach us not 
only that the child may suffer physically and mentally, 
but that his whole character may be greatly modified, or 
even changed, by the condition of the eyes. 

Perhaps at no physical point has the development of 
man borne more heavily upon him than in the matter of 



—37— 

his eyesight, not with-standing the wonderous power and 
facility of that sense and the marvelous inventions in its 
aid . The eye is the nurse and foster mother of all the other 
senses and the patron of all the arts and sciences, and the 
modern man is looking minutely into a myriad of things 
and taxing his eyesight accordingly, and many are the 
hopes that have failed and bitter has been the disappoint- 
ment when eyesight has given way under the stress and 
ceasless burden of the varied avocations and professions 
of modern life, at last we are begining to realize what an 
endless train of terrible evils attend upon the breaking 
down and destruction of the eye under this stress and bur- 
den, and not the least of these evils is the overstrain on the 
already overtaxed nervous system. 

That extreme, near sightedness for example, would 
have any effect on the brain. I do not believe objects, to 
the near sighted man, appear the same within the range 
of his vision as they do to the man with normal eyes. 
The only difference is that its world is more limited; what 
he sees, he sees as well, only he does not see as far. If the 
brain is normal his impressions are normal. Of course, if 
his brain is abnormal, no matter how nearly perfect the 
eye as an organ is, the impression the brain receives 
through it are likely to be abnormal. 

These impressions may be affected by the condition of 
the eye, however, as in cases where a man is suffering from 
alcoholism for instance, the curious things a man sees 
when suffering from alcoholism are partly due to the brain 
disturbance and partW due to the condition of his eyes. 
When hesees snakes, it is not entirely dueto hallucination; 
it is partly due to the condition of his eye. When he sees 
as in Kipling's Lu Nuit Blanche: a blood-red mouse; it is 
due as much to the engorged blood vessel of the eyes as to 
a freak of imagination. 



*UG 10 1903 






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